It has been found that the periodic arrangement of second conductor patterns having a specific structure (hereinafter, described as a metamaterial) enables control of the propagation characteristic of an electromagnetic wave. Examples of a related technology with respect to the metamaterial include a technology described in Patent Documents 1 and 2. The technology described in Patent Document 1 relates to a structure, a so-called mushroom-type metamaterial in which a plurality of island-shaped second conductor patterns is disposed above a sheet-shaped second conductor pattern, and each of the island-shaped second conductor patterns is connected to the sheet-shaped second conductor pattern through a via.
The metamaterial has a property of suppressing propagation of electromagnetic waves in a specific frequency band. If the metamaterial structure is introduced to the interconnection substrate, the noise may be prevented from propagating at the inside of the interconnection substrate (for example, Patent Document 3).